The broad concept of a firearm designed for one type of ammunition, such as high powered center fire cartridges, and convertible to a second form of ammunition, such as 22 calibre rimfire cartridges, is known in the prior art. One example of the patented prior art showing such a convertible firearm is U.S. Pat. No. 3,776,095, issued Dec. 4, 1973 to Atchisson.
The general object of the present invention is to improve on the known prior art by providing an easily and quickly convertible sporting rifle of the semi-automatic type which may be fired as rapidly as the trigger can be pulled in both forms or versions of the invention. The invention was conceived with the idea of converting a high powered sporting rifle at little cost to a 22 calibre rimfire rifle for small game hunting, target practice, indoor shooting, and the like, in the belief that such a convertible firearm would appeal to a variety of gun enthusiasts.
Governing factors in the designing of the firearm were simplicity of construction, ease of assembly and disassembly, ruggedness and durability, simplicity and safety in operation, aesthetic appeal, and the capability of mounting all types of open sights and scopes.
A further and more specific objective of the invention is to provide a convertible semi-automatic sporting rifle of the mentioned type which has fewer and less complex parts than the known prior art, and in which there is absolutely no possibility of assembling the rifle incorrectly in either version thereof.